I'm planning to create a web site that runs on several different machines in Google Cloud Compute, and I'm serious thinking to use the Network Load Balancing of Google. But I have some questions regards security and usability.
My machines can have a private ip address with the http port opened ?( we don't when some hacker is trying to get in ours servers)
My http response will have the machine own ip address or the ip in the Network Load Balance ?
Does Google protect the opened port in Google Cloud Compute machine against SYN,Pack flow attacks( like a router)?
You could use the HTTP/S load balancing to do what you want. https://cloud.google.com/compute/docs/load-balancing/http/
See https://cloud.google.com/compute/docs/load-balancing/http/cross-region-example#optional_remove_external_ips_except_for_a_bastion_host for removing external IPs.
Responses will come from the load balanced IP, not your VMs' IPs.
Yes for some types of malicious traffic, because the load balancing layer is doing full proxying. This means TCP and SSL termination both happen before your VMs.
if your machines have only private IP (RFC 1918 space) and no external IP, then configuring NLB doesn't make them externally accessible directly on port 80 (if thats what you configure for your service).
google does handle some level of attacks, but if you are like for a full-fledged ddos, then implementing additional layer on your end helps.
No. Is only possible to have the port 80(http) open if and only if the instance has a public ip address; however, it is possible to limit the machine instances affected with a bastion host.
No. Using the Network Load Balance will protect the ip address of you machine, but is possible (in theory) to gather the machine external ip address with random ip address scans or some flaw in the application.
GCE machine instances have some sort of protection, but they are susceptible to TCP or UDP flood according to securityfocus.
Related
I have a Python application which has been deployed to openshift.
I am using an external REST service in my application. In order to use this service, the developers of the REST service have to whitelist my IP because a Firewall blocks unauthorized IP addresses.
How can I find the external IP of my application? How can I find it in openshift? I tried a few OC commands, but I am not sure if I have to get the IP of the pod or the service.
Out of the box the traffic from internal cluster components will appear to external infrastructure like they are coming from whichever OpenShift compute host their pods are currently scheduled on.
Information on internal cluster networking and how traffic traverses from a process running inside a pod to the external network can be found at SDN: Packet Flow.
In your case you could have the external application whitelist all of the ip addresses of the compute hosts that are expected to run your application pods.
Alternately you could set up an EgressIP. This will cause all traffic originating from a specific OpenShift project to appear as if it is originating from a single ip address. You could then have your external application whitelist the EgressIP address.
Documentation for configuring EgressIP can be found in the official documentation under Enabling Static IPs for External Project Traffic
What you are searching for is the external IP of the Service. A Service acts as a load balancer for your pods but by default it only has a cluster-wide IP address. If you need a URL to access it from the outside, you can create a Route. For your purpose where you need an actual external IP address, you can assign the Service an external IP manually. Information on how to do this can be found in the official OpenShift Docs.
I'm trying to build a webserver in Google Cloud Platform that hosts multiple websites (GBP, IE, FR, DK etc.)
Generally, we assign a range of IPs to the server statically, set the bindings in IIS, then loadbalance using a virtual IP.
It seems near enough impossible to assign another internal IP in GCP. Lots of guides about additional external IPs, but we don't want a public facing webserver like this.
Anybody have any idea on how to add additional internal IPs to a VM / Instance?
Also, I have tried changing the internal address I have assigned to the Instance to static in network adapter settings, next thing I know I can't access my VM for love nor money, had to delete and re-create. If I go into advanced settings to add additional static IPs, w'ere set to DHCP apparently, so can't add additional IPs.
Thanks all.
Answer that I recieved from GCE discussion group, in Google Groups:
"You can add additional internal IP addresses to a VM instance. This is possible by enabling IP forwarding for the VM, creating a static network route, adding appropriate firewall rules, and setting additional internal IP addresses to network adapter of Windows. These steps are described in this article for Linux machines (https://cloud.google.com/compute/docs/networking#set_a_static_target_ip_address). The same steps are valid for Windows VMs. You will need to keep the initial internal IP address, subnet mask, gateway address and DNS settings of the adapter and manually enter them in properties of IPv4 of the network adapter. The below is a screenshot of my configuration on a VM instance (Windows 2008 R2) that perfectly works."
Update:
Now, you can create instances with multiple network interfaces On Google Compute Engine and assign IPs. For more information, refer to this public documentation link. However, currently it has following limitations:
Alias IP ranges are not supported on any network interface on a VM
that has multiple network interfaces enabled.
You cannot modify or delete the network interfaces after the VM has
been created.
I have a MySQL database running on my raspberry pi.
To access it I use dynamic DNS (duckdns) when I am outside of my network, but I would like to access it with same dynamic domain name when I am inside my network. However it is not working and I always get connection refused.
I would like somehow enable it so I do not have to change in app.config MySQL server address from my dynamic domain to localhost when I am inside my local network.
You'll need a gateway router that supports NAT hairpinning. Many consumer-grade units (and some supposedly commercial-grade equipment) doesn't support this. Either yours doesn't, or you need to find an option to enable it.
When you try to connect to the public IP address from inside the network, the router probably assumes that you want to connect to the router itself.
My cable modem's built-in router at home understands how to do this. When I access my server from the laptop, and connect to the public IP from inside, the router (inside the cable modem) does a transformation on the packets so that my server sees my connection coming from the router's IP address, not my laptop's IP address.
This is what has to happen, because when the server responds, it will respond to the machine that connected to it. If it responded to the laptop's address, the laptop would reject the traffic, since it would be coming from ther server's internal IP, which is not the IP address I connected to. So, it responds to the router, which does a second transform on the packet address, replacing the server's internal IP with the external IP. Remembering the session from previous traffic, the router then sends the packet back to the laptop.
Ultimately this setup can't possibly work for you without the complicity of your router, which may not have that capability.
Some routers, however, have a DNS proxy that will allow you to create static entries. My former DSL modem could not hairpin NAT connections, but it had a way to create DNS entries that would be used to respond to internal DNS queries for a specific host... with a different IP than the one that DNS otherwise provided. That's an alternative workaround if the router supports it.
We have a system running on Amazon's Beanstalk.
We would like to limit access to the server to HTTPS only.
When blocking HTTP on the environment settings - it prevents accessing through the beanstalk DNS.
However, if someone knows the public IP (or name) of any of the servers - he can access them directly through HTTP. It seems that the LB forwards the requests to port 80, so we can not change the security group and remove port 80.
Is there a simple way, to limit HTTP access to be only from the LB?
Thanks
You should be able to do this through EC2 Security Groups, which is an Elastic Beanstalk environment property.
By default this allows connections to port 80 from any IP address, but you could remove that rule or replace it with your own IP address (for testing purposes).
Failing that, you could reroute all HTTP traffic to HTTPS at the application level or simply test the CGI property *server_port_secure* and refuse to answer.
Yes, you need http/80 to be open for health-check to work. The option for you is to redirect all the other requests (except the health check URL) to use https - This way though the port is open, you "dont serve any data in an insecure way".
You have at least two options:
1 - set the Security Group Policy that allows access on port 80 from the Load Balancer only. IMPORTANT!!! Do not use the Load balancer IP in the instances' security group. Use the Load balancer security group ID instead.
2 - remove the public IPs from the instances. You should be good if all your EC2 instances have a private IPs and the ELB has a public IP.
Assume that there is a web-page called whatisyourip.com and that I have a web-page called changeip.com. A user wants to enter the site whatisyourip.com through changeip.com. Normally, changeip.com would be a proxy server so the user can hide his ip address. That's how users reach forbidden web-pages in their countries. But I want to ask, is there a way to show a different ip address to whatisyourip.com while connecting it through changeip.com without using it as a proxy server?
is there a way to show a different ip address to whatisyourip.com while connecting it through changeip.com without using it as a proxy server?
Short answer: Yes. Make changeip.com a VPN server and assign different IP addresses to those VPN clients. Ensure they send all traffic through the VPN. This usually involves modification of the local routing table on the VPN client workstations for everything to work correctly.
Longer answer... There are several reliable ways to hide IP addresses of TCP sessions...
HTTP Proxy - you already described this situation
Network address Translation - this doesn't sound likely in your scenario
VPN Tunneling - Possible solution instead of HTTP proxy, even if it's something as simple as an SSL VPN. Depending on your constraints, this could also be a viable option.
You can't. TCP connections require a 3-way handshake. You can certainly send a SYN packet to the server to start the process, then change your IP address. but when the site responds with the 2nd-stage of the handshake (SYN+ACK), that packet is now going to your old IP address and your system will drop it - it has no idea that the server is responding to something that was started on the old IP.
You could try something like the Tor network, which offers end-to-end encryption of traffic and cloaking of origins, but it's not something I'd consider "reliable".
Not unless you spoof your IP, in which case the response will go to the forged IP. So no.